The present invention relates to a method of biological control to inhibit and suppress fungal infections or infestations using a treated Spirulina compound as the controlling or inhibiting agent. The present invention further relates to a method of biological control of organisms and animals and more particularly, pests and diseases associated with pests, using a treated Spirulina compound as the controlling or inhibiting agent.
Spirulina is approved for human and animal consumption as a protein source under international food and drug standards. It also contains carotenoids, vitamins and minerals (Hayashi and Hayashi, xe2x80x9cCalcium Spirulan, an Inhibitor of Enveloped Virus Replication, from Blue-Green Alga Spirulina platensisxe2x80x9d, J. Nat Prod (1996), 59, p. 83).
Spirulina have also been found to have anti-viral abilities, as can be seen in the above article and in U.S. Pat. No. 5,585,365 (Hayashi et al). A hot water extract of Spirulina from which a calcium polysaccharide was purified was disclosed. The purified extract was effective for the treatment of viral diseases.
In U.S. Pat. No. 4,845,085 (Sesin) a semi-synthetic compound derived from Nostoc sp. is disclosed as having anti-fungal abilities. However this compound is disclosed as best for only filamentous fungi. Secondary metabolites from species such as Spirulina have also been used as anti-fouling agents (DE19646324 (Abstract)).
In addition Spirulina has been reported as having biological activity for example: to lower blood sugar levels (in diabetes); to lower blood cholesterol; and other effects (Hayashi et al). Other biological activity for Spirulina has been disclosed, for example by Amirani (Chemical Abstracts, 91:169142n); in U.S. Pat. No. 4,886,756 (Kawamura) disclosing a restriction endonuclease from Spirulina; and in J 6303391 (Abstract) a method is disclosed for producing a physiologically active substance from Spirulina.
The use of an agent to hinder the establishment of a competitive organism (pest or contaminant) or to promote the growth of a companion organism is known.
However, at present there is no method of biological control to inhibit and suppress competitive organisms whereby the mutualistic association between the agent and companion organism can be maintained via an external factor without alteration of the agent genotype.
The inventors are not aware of any reports that suggest Spirulina is specifically an antifungal agent (or fungicide) nor that Spirulina can act as an agent for biological control of agricultural and horticultural pests.
It is an object of the present invention to overcome this absence by the use of a treated Spirulina compound. It is a further object of one aspect of the present invention to provide an improved method of biological control whereby the vigour of the agent can be controlled by the exclusion of visible light.
The present invention provides a method of biological control to inhibit and suppress the growth and effects of fungal contaminants associated with a companion organism (a target partner entering into a mutualistic association with an anti-fungal agent), in which said anti-fungal agent is a treated Spirulina compound, said method including the steps of:
preparation of the treated Spirulina compound; and
the application of said compound on or adjacent a target site which site is selected from the group consisting of: horticultural products; mushroom spawn; agricultural products; and a combination thereof; wherein
said preparation includes the steps of rehydrating desiccated Spirulina, stressing the culture and freeze drying to a powder.
Preferably, said method further includes a means to control the vigour of said agent, said means being visible light, and wherein said agent is applied as a liquid culture spray.
Advantageously, the intensity of the chlorophyll green colouration of the agent may be used as an indicator of shelf life of a proprietary preparation.
The present invention also provides a method of biological control to inhibit, suppress or remove biological pests wherein a pesticidal agent is used, said agent being a treated Spirulina compound, said method comprising the steps of:
preparation of the treated Spirulina compound; and
the application of said compound on or adjacent a target site, said site being selected from the group consisting of: the fluid containing the pests to be suppressed, removed or controlled; and a bait station in or adjacent the source of the pests or along a known flight path of said pests; wherein
said preparation includes the steps of rehydrating desiccated Spirulina, stressing the culture and freeze drying to a powder.
Preferably such pests are crustacea and insects, and more particularly, insects regarded as pests in the fields of agriculture, horticulture and medicine. Preferably also the bait station may include a known lure for the pests.